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Item Adsorption of Carbon Monoxide on Copper (100) Studied by Photoelectron Spectroscopy and Low Energy Electron Diffraction(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1978, 74(3), 1978) Isa, Saadoon A.; Joyner, Richard W.; Roberts, M. WynBy combining u.v. and X-ray photoelectron spectroscopy with low energy electron diffraction, Cu(100) has been shown to adsorb carbon monoxide at 295 K. Adsorption, although molecular, has distinctly different spectroscopic characteristics from adsorption at 80 K. The oxygen (1s) binding energy is 1.3 eV lower at 295 K than at 80 K, the carbon 1s binding energy is also lower. The sticking probability is ∼10–6 at 295 K although close to unity at 80 K, and the energy of desorption is greater for the room temperature state. The LEED pattern, (√2 ×√2)R45° is the same as observed at 80 K (for θ < 0.5) but the maximum coverage is substantially smaller at 295 K (θ∼ 0.3) and the diffraction spots more diffuse. At 80 K the photoelectron spectroscopy and LEED data are similar to those observed previously. Changes in the u.v. induced spectra with increasing CO coverage are shown to reflect the onset of LEED “compression structures” rather than the presence of two adsorbed phases of carbon monoxide. We suggest that the existence of two distinct types of CO bonding on copper (100), (at 295 and 80 K) is a consequence of the molecule acting more as an electron acceptor, (“COδ–”) at 295 K and more like an electron donor, (“COδ+”) at 80 K. The presence of a chemisorption level 1.5 eV below the Fermi edge, i.e. in the s-band region of the spectrum, is interpreted as being due to reorganisation of metal s and d electrons which is in keeping with the transition metal-like characteristics of the adsorption at 295 K.Item Kinetics and Kinetic Oscillation in Carbon Monoxide Oxidation(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (09), 1974) Yang, Ching H.; Berlad, Abraham L.A kinetic mechanism is proposed for the low temperature oxidation of carbon monoxide. A general mathematical model which conserves all reactants, catalytic impurities and intermediate species is formulated to contain all proposed reactions without invoking the assumption of steady states. Numerically integrated solutions predict the observed kinetic behaviour of glow, explosion and oscillation. Particular effort has been directed to the study of the various characteristics connected with kinetic oscillations observed in the oxidation of carbon monoxide in both dry and wet mixtures.Item Oxygen Negative ton Reactions with Carbon Dioxide and Carbon Monoxide(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (1), 1973) Parkes, David A.Item Adsorption of Carbon Monoxide by Zeolite Y Exchanged with Different Cations(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (1), 1973) Egerton, T. A.; Stone, F. S.Adsorption of carbon monoxide has been studied on Zeolite Y in which Na* ions have been partially exchanged for Zn2+, Mn2\ Co2+, Ni2% Cu2+, Ba2+, UOf and Cc3+ ions. The divalent ions all produced sites for specific CO adsorption, even at low degrees of exchange. Thus, unlike Ca2^ studied in earlier work, these ions do not have a total preference for internal sites in the prisms or sodalite units inaccessible to CO. At approximately 30 % exchange the affinity of divalent ions for internal sites decreases in the order Ca2+ > Ni2i, Mn2+, UOr > Cu2+ > Zn2+. However, even on the Zn-exchangcd Y, only about 1 divalent ion in 10 acts as a site for specific adsorption of CO. Very little CO was specifically adsorbed on Ce-exchanged Y, even at high degrees of exchange. This confirms that cerium ions favour internal sites. With ZnY, MnY, BaY and CeY, CO adsorption was rapid and reversible. Isosteric heats were evaluated and, except for CeY, were substantially greater than on uncxchanged NaY, confirming the presence of specific adsorption. The heats correlate with the electrostatic field strengths of the cations and with the shifts of the C—O stretching frequency on adsorption. With NiY and CuY, adsorption was slow and is thought to reflect a gradual increase in the number of adsorption sites caused by adsorbate-induced migration of divalent cations. A number of the systems studied in this work have not previously been investigated from the standpoint of cation location. However, where comparisons arc possible, the present results derived from CO adsorption are shown to be in good agreement with those from other methods.Item Oxygen Negative Ion Reactions with Carbon Dioxide and Carbon Monoxide: Part 1(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (4), 1972) Parkes, David A.A drift tube and mass filter have been used to measure the rates of some O– negative ion molecule reactions, thought to be important in the radiolysis of carbon dioxide. Measurements of the clustering reaction O–+ CO2+ M → CO–3+ M in carbon dioxide give a third-order rate constant which falls with increasing pressure. This suggests an intermediate CO–3 ion with a lifetime of approximately 10–8 s. The limiting, low-pressure, rate constant is (1.1 ± 0.1)× 10–27 cm6 molecule–2 s–1 and, in the high-pressure limit, it is (2.7 ± 0.3)× 10–10 cm3 molecule–1 s–1. The rate also falls slowly with increasing reduced field. In O2 the rate constant is a factor of 3.5 lower, but it is difficult to measure the pressure dependence as accurately because CO–3 is also produced by the reaction: O–3+ CO2→ CO–3+ O2k=(5.5 ± 0.5)× 10–10 cm3 molecule–1 s–1. The rate constant measured in O2 for the associative detachment reaction O–+ CO → CO2+ e is (7.3 ± 0.7)× 10–10 cm3 molecule–1 s–1. Similar experiments in carbon dioxide are complicated by changes in the electron energy distribution as CO is added, but an upper limit of significantly less than 10–13 cm3 molecule–1 s–1 is suggested for the competing reaction: CO–3+ CO → 2CO2+ e. The reaction of O–3 with CO is very slow.